Limited Reuse Ablation Needles and Ablation Devices for Use Therewith

ABSTRACT

A surgical instrument includes a reusable component and a limited-use component. The reusable component includes a first electrical contact. The limited-use component is releasably engagable with the reusable component. The limited-use component includes a second electrical contact configured to electrically couple to the first electrical contact to establish electrical communication between the reusable component and the limited-use component. The second electrical contact is movable from a first position, wherein the second electrical contact is positioned to electrically couple to the first electrical contact upon engagement of the limited-use component and the reusable component to one another, to a second position, wherein the second electrical contact is positioned to inhibit electrical coupling to the first electrical contact upon engagement of the limited-use component and the reusable component to one another.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patent application Ser. No. 13/460,414 filed on Apr. 30, 2012, the entire contents of which are incorporated herein by reference.

BACKGROUND Technical Field

The present disclosure relates to surgical instruments and, more particularly, to ablation devices including disposable needles configured for single-use or a limited amount and/or number of uses.

Background of Related Art

Energy-based tissue treatment is well known in the art. Various types of energy (e.g., electrosurgical, ultrasonic, microwave, cryogenic, thermal, laser, etc.) are applied to tissue to achieve a desired result, e.g., to cut, ablate, coagulate, and/or seal tissue.

Electrosurgery involves the application of radio frequency (RF) energy to a surgical site to cut, ablate, coagulate, and/or seal tissue. In monopolar electrosurgery, a source or active electrode, which is typically part of the surgical instrument held by the surgeon, delivers RF electrical current from a generator to tissue, while a patient return electrode is placed remotely from the active electrode to carry the current back to the generator.

In tissue ablation electrosurgery, for example, the RF energy may be delivered to targeted tissue by a probe or needle. More specifically, in use, the needle is typically advanced through tissue to a desired position either prior to or during application of energy to tissue. After repeated use, these needles may become dull, bent, or otherwise deformed and, consequently, may become more difficult to place and operate upon subsequent use. As such, ablation devices have been developed which include replaceable needles, thus allowing the needle to be replaced after one or more uses without requiring replacement of the entire device (e.g., the handpiece).

SUMMARY

As used herein, the term “distal” refers to the portion that is being described which is further from a user, while the term “proximal” refers to the portion that is being described which is closer to a user. Further, to the extent consistent with one another, any of the aspects described herein may be used in conjunction with any of the other aspects described herein.

In accordance with aspects of the present disclosure, a surgical instrument is provided generally including a reusable component and a limited-use component. The reusable a component includes a first electrical contact. The limited-use component is releasably engagable with the reusable component and includes a second electrical contact configured to electrically couple to the first electrical contact to establish electrical communication between the reusable component and the limited-use component. The second electrical contact is movable from a first position, wherein the second electrical contact is positioned to electrically couple to the first electrical contact upon engagement of the limited-use component and the reusable component to one another, to a second position, wherein the second electrical contact is positioned to inhibit electrical coupling to the first electrical contact upon engagement of the limited-use component and the reusable component to one another.

In one aspect, the surgical instrument includes an ablation device having a reusable handle assembly and a limited-use needle electrode assembly releasably engagable with the handle assembly. In such aspects, in the first position, the second electrical contact may be disposed at a proximal end of the limited-use needle electrode assembly to facilitate engagement to the first electrical contact of the reusable handle assembly. In the second position, on the other hand, the second electrical contact may be retracted into the limited-use needle electrode assembly to inhibit electrical coupling to the first electrical contact.

In another aspect, the second electrical contact is coupled to a biasing member and is supported via a support member. In such aspects, the support member is configured to transition from a first condition, wherein the support member retains the second electrical contact in the first position against the bias of the biasing member, and a second condition, wherein the support member no longer supports the second electrical contact, thereby permitting the second electrical contact to move to the second position under the bias of the biasing member.

In yet another aspect, the support member is transitioned from the first condition to the second condition upon application of a fluid thereto, heating to a pre-determined temperature, application of electrical energy thereto, and/or application of chemicals thereto.

In still another aspect, the support member is formed from a dissolvable material, a phase-change material, or a collapsible scaffold.

In yet another aspect, the second electrical contact is supported by a retention element. The retention element is transitionable from a first condition, wherein the retention element retains the second electrical contact in the first position, and a second condition, wherein the retention element effects movement of the second electrical contact to the second position.

In still yet another aspect, the retention element is transitioned from the first condition to the second condition upon application of a fluid thereto, heating to a pre-determined temperature, application of electrical energy thereto, and/or application of chemicals thereto.

In another aspect, electrical communication between the first and second electrical contacts is configured for transmitting electrical energy to the reusable component and/or identifying the reusable component.

Another surgical instrument provided in accordance with aspects of the present disclosure generally includes a reusable component including a first electrical contact and a limited-use component releasably engagable with the reusable component. The limited-use component includes a second electrical contact configured to electrically couple to the first electrical contact to establish electrical communication between the reusable component and the limited-use component. The second electrical contact is movable from a first position, wherein mechanical engagement of the reusable component and the limited-use component is permitted, to a second position, wherein the second electrical contact inhibits mechanical engagement of the reusable component and the limited-use component to one another.

In one aspect, the surgical instrument includes an ablation device having a reusable handle assembly and a limited-use needle electrode assembly releasably engagable with the handle assembly.

In another aspect, the first electrical contact includes a first pin and the second electrical contact includes a second pin. In the first position, the second pin is positioned to permit insertion of the first pin at least partially into the limited-use component to permit mechanical engagement of the reusable component and the limited-use component to one another. In the second position, the second pin is positioned to inhibit insertion of the first pin into the limited-use component, thereby inhibiting mechanical engagement of the reusable component and the limited-use component to one another.

In another aspect, the second electrical contact is transitioned from the first position to the second position upon heating to a pre-determined temperature. Further, the second electrical contact may be formed partially (or entirely) from a ferromagnetic material or a shape-memory material.

In yet another aspect, electrical communication between the first and second electrical contacts is configured for transmitting electrical energy to the reusable component and/or identifying the reusable component.

A surgical instrument provided in accordance with aspects of the present disclosure includes a reusable component including a first electrical contact and a limited-use component releasably engagable with the reusable component. The limited-use component includes a second electrical contact that is configured to electrically couple to the first electrical contact to establish electrical communication between the reusable component and the limited-use component. The second electrical contact is incorporated within a self-destructible cell that is configured for transitioning between an operable condition, wherein electrical communication is established between the first and second electrical contacts upon coupling of the first and second electrical contacts to one another, and a destroyed condition, wherein electrical communication between the first and second electrical contacts is inhibited.

In one aspect, the second electrical contact is incorporated into a galvanic cell that is configured to corrode to inhibit electrical communication between the first and second electrical contacts.

In another aspect, electrical communication between the first and second electrical contacts is configured for transmitting electrical energy to the reusable component and/or identifying the reusable component.

BRIEF DESCRIPTION OF THE DRAWINGS

Various aspects of the present disclosure are described herein with reference to the drawings wherein like reference numerals identify similar or identical elements:

FIG. 1 is a side view of an electrosurgical ablation system provided in accordance with the present disclosure;

FIG. 2 is a longitudinal, cross-sectional view of the electrosurgical ablation system of FIG. 1;

FIG. 3A is a longitudinal, cross-sectional view of an electrosurgical ablation device provided in accordance with the present disclosure wherein a needle electrode assembly of the electrosurgical ablation device is disposed in a usable condition and is disengaged from a handle assembly thereof;

FIG. 3B is a longitudinal, cross-sectional view of the needle electrode assembly of FIG. 3A shown in a spent condition;

FIG. 4A is a longitudinal, cross-sectional view of an electrosurgical ablation device provided in accordance with the present disclosure wherein a needle electrode assembly of the electrosurgical ablation device is disposed in a usable condition and is disengaged from a handle assembly thereof;

FIG. 4B is a longitudinal, cross-sectional view of the needle electrode assembly of FIG. 4A shown in a spent condition;

FIG. 5A is a longitudinal, cross-sectional view of another electrosurgical ablation system provided in accordance with the present disclosure wherein a needle electrode assembly is disengaged from a handle assembly thereof;

FIG. 5B is a longitudinal, cross-sectional view of the electrosurgical ablation system of FIG. 5A wherein the needle electrode assembly is engaged to the handle assembly;

FIG. 5C is a longitudinal, cross-sectional view of the needle electrode assembly of FIGS. 5A-5B shown in a spent condition;

FIG. 6 is a longitudinal, cross-sectional view of another electrosurgical ablation system provided in accordance with the present disclosure showing a needle electrode assembly engaged to a handle assembly thereof;

FIG. 7A is a longitudinal, cross-sectional view of another electrosurgical ablation system provided in accordance with the present disclosure wherein a needle electrode assembly is disengaged from a handle assembly thereof;

FIG. 7B is a longitudinal, cross-sectional view of the electrosurgical ablation system of FIG. 7A showing the needle electrode assembly mechanically engaged to the handle assembly; and

FIG. 7C is a longitudinal, cross-sectional view of the electrosurgical ablation system of FIG. 7A showing the needle electrode assembly mechanically engaged and electrically coupled to the handle assembly.

DETAILED DESCRIPTION

Referring initially to FIGS. 1-2, an ablation system provided in accordance with the present disclosure is shown generally designated by reference numeral 10. Although ablation system 10 is shown configured as an RF-ablation system 10, the present disclosure is equally applicable for use with microwave ablation systems, or any other suitable surgical system including single-use or limited-use disposable components. Obviously, different considerations apply depending on the particular device and/or system used; however, the novel aspects with respect to inhibiting or limiting re-use of the needle (or other component) remains generally consistent regardless of the particular type of device and/or system used. For the purposes herein, ablation system 10 is generally described.

Continuing with reference to FIGS. 1-2, ablation device 100 of ablation system 10 generally includes a handle assembly 110 and a needle electrode assembly 150 releasably engagable with and extending from handle assembly 110. Although only one needle electrode assembly 150 is shown, additional needle electrode assemblies, either similar to or different from needle electrode assembly 150, may be provided for releasable engagement with handle assembly 110. As such, a desired needle electrode assembly may be selected and engaged to handle assembly 110, depending on a particular purpose and/or to replace a “spent” needle, e.g., a used needle, in the case of single-use needles, or a needle that has reached its usage limit and/or its maximum number of uses, in the case of limited use needles.

Handle assembly 110 includes a housing 112 which may be ergonomically or otherwise configured to facilitate the grasping and manipulation of housing 112 by a user to position needle electrode assembly 150 as desired. Housing 112 is formed from an insulative material and defines proximal and distal ends 113, 115, respectively. Proximal end 113 of housing is configured to receive lines 22, 32 from an energy source, e.g., generator 20, and cooling fluid source 30, respectively, for supplying energy and cooling fluid, respectively, to needle electrode assembly 150. Distal end 115 of housing 112 defines an engagement recess 116 configured to receive proximal end 152 of needle electrode assembly 150 therein for engaging needle electrode assembly 150 and handle assembly 110 to one another. More specifically, engagement recess 116 of housing 112 defines one or more notches 118 therein that are configured to engage protrusions 154 extending outwardly from proximal end 152 of needle electrode assembly 150 upon insertion of needle electrode assembly 150 into engagement recess 116 of housing 112 for releasably mechanically engaging needle electrode assembly 150 and handle assembly 110 to one another. Other releasable engagement mechanisms, e.g., snap-fit engagements, threaded-engagements, friction-fit engagements, etc., are also contemplated.

With continued reference to FIGS. 1-2, handle assembly 110 further includes a pair of electrical contacts 122 (although greater or fewer contacts are also contemplated) disposed on the base surface of engagement recess 116 that are configured to electrically couple to corresponding electrical contacts 172 positioned at proximal end 152 of needle electrode assembly 150 upon mechanical engagement of handle assembly 110 and needle electrode assembly 150 to one another, thereby establishing electrical communication between handle assembly 110 and needle electrode assembly 150 upon mechanical engagement of handle assembly 110 and needle electrode assembly 150 to one another. One or more wires 123 extending through housing 112 of handle assembly 110 couple contacts 122 to line 22, which extends proximally from housing 112 of handle assembly 110, ultimately coupling to generator 20. As such, power and/or control signals may be transmitted between generator 20 and needle electrode assembly 150 via the pairs of electrically-coupled contacts 122, 172. In particular, contacts 122, 172 may be configured for establishing a conductive path for transmission of energy between generator 20 and needle electrode assembly 150. As such, upon activation, energy can be transmitted from generator 20 to needle electrode assembly 150, e.g., via line 22, wires 123, and contacts 122, 172, and, ultimately, conducted through tissue to ablate or otherwise treat tissue. As an alternative to external generator 20, it is contemplated that generator 20 be incorporated into handle assembly 110, thus providing a hand-held ablation device 100.

One of the pairs of contacts 122, 172 may be utilized for identifying or verifying the identification of the particular type of needle electrode assembly 150 engaged with handle assembly 110. This feature helps ensure that an acceptable needle electrode assembly 150 has been engaged to handle assembly 110 and/or that the proper energy delivery and control parameters for the particular needle electrode assembly 150 engaged with handle assembly 110 are provided by generator 20. Additionally or alternatively, the same or a different pair of contacts 122, 172 may be utilized to indicate the number of times that the particular needle electrode assembly 150 engaged with handle assembly 110 has been used. Further, the operation of cooling fluid source 30 may also be at least partially dependent upon the particular type of needle electrode assembly 150 detected. Thus, identifying information for the particular type of needle electrode assembly 150 engaged to handle assembly 110 may be relayed to and utilized by cooling fluid source 30 for controlling the supply of cooling fluid to needle electrode assembly 150 in accordance therewith. Other configurations of contact(s) or similar features for establishing electrical communication and electrical energy transmission between handle assembly 110 and needle electrode assembly 150 are also contemplated.

Needle electrode assembly 150 defines a longitudinal axis “X-X” and includes an electrically-conductive needle 170 defining a hollow interior 174, an insulative sleeve 180 (or coating) disposed about a portion of the external surface of needle 170, and, as mentioned above, one or more electrical contacts 172 configured to permit electrical coupling of needle 170 to handle assembly 110 upon mechanical engagement of needle electrode assembly 150 and handle assembly 110 to one another.

Proximal end 152 of needle electrode assembly 150 is configured for insertion into engagement recess 116 of housing 112 of handle assembly 110 and includes a pair of outwardly-extending protrusions 154 (or other suitable complementary structure) configured to releasably engage notches 118 defined within engagement recess 116 of handle assembly 110 to releasably engage needle electrode assembly 150 within engagement recess 116 of handle assembly 110.

Continuing with reference to FIGS. 1-2, needle 170 extends distally from engagement recess 116 of housing 112 of handle assembly 110 to distal end 176 thereof, which defines a distal tip 178 configured to facilitate the penetration of tissue while minimizing the risk of hemorrhage from the puncture tract, although other distal tip configurations are also contemplated. Needle 170 is formed from an electrically-conductive material of which at least distal end 176 is exposed. An insulating sleeve 180, or coating of material, surrounds the remaining portion of needle 170 that extends distally from engagement recess 116. With at least distal end 176 of needle 170 exposed, energy, e.g., RF energy, can be delivered from needle 170 to surrounding tissue to treat, e.g., ablate, tissue.

As mentioned above, an energy source, e.g., generator 20, is provided for providing power and/or control signals to needle electrode assembly 150 via line 22, one or more wires 123, and one or more pairs of contacts 122, 172. Further, a cooling fluid source 30 is provided for providing cooling fluid to needle electrode assembly 150. Cooling fluid source 30 provides cooling fluid, via line 32 (which includes both inflow and outflow lines), such that cooling fluid supplied by the cooling fluid source 30 may be circulated through hollow interior 174 of needle 170 to maintain needle electrode assembly 150 in a relatively cooled state during the application of energy to tissue. Cooperating valves 179, 129 of needle electrode assembly 150 and handle assembly 110, respectively, may be provided to facilitate the passage, e.g., inflow and outflow, of cooling fluid between cooling fluid source 30 and hollow interior 174 of needle 170, although other configurations are also contemplated. Circulation of the cooling fluid may be established through the use of a pump (not shown) or other suitable mechanism disposed within housing 112 of handle assembly 110, or the pump (not shown) may be externally disposed.

In operation, ablation device 100, lead by distal tip 178 of needle 170, is inserted into an operative site such that exposed distal end 176 of needle 170 of ablation device 100 is positioned adjacent to or within a target tissue to be treated, e.g., ablated. A return pad or return electrode (not shown) may, at this point or prior to, be operatively adhered to or connected to the patient. With exposed distal end 176 of needle 170 in position, energy, e.g., RF energy, is delivered from generator 20 to needle 170 and is conducted from exposed distal end 176 of needle 170 through the target tissue, ultimately to be collected by the return electrode (not shown). An effective amount of energy at an effective energy level and for an effective duration of time is delivered to tissue to achieve the desired result, e.g., to treat the target tissue. To this end, one or more control switches 130 may be provided on handle assembly 110 for controlling the supply of energy to needle 170, or, alternatively, the supply of energy may be automatically or manually controlled by generator 20.

Either prior to or simultaneously with the delivery of electrosurgical energy to needle 170, the cooling fluid provided by cooling fluid source 30 may be circulated through hollow interior 174 of needle 170 to withdraw heat from needle 170, thus maintaining needle 170 in a relatively cooled state during use. The delivery of cooling fluid to hollow interior 174 of needle 170 may likewise be controlled by one or more control switches 130 disposed on handle assembly 110, or via cooling fluid supply 30 itself.

At the completion of the procedure, needle electrode assembly 150 may be disengaged from handle assembly 110 and discarded, in those embodiments where needle electrode assembly 150 is configured as a single-use component or where needle electrode assembly 150 has reached its usage limit or maximum number of uses, or may be sterilized for re-use, in those embodiments where needle electrode assembly 150 has yet to reach its usage limit or maximum number of uses. Handle assembly 110 is configured as a reusable component and, thus, is sterilizable for re-use, although handle assembly 110 may also be configured as a disposable component.

Turning now to FIGS. 3A-3B, 4A-4B, 5A-5C, and 6, various different embodiments of ablation devices including needle electrode assemblies similar to needle electrode assembly 150 (FIGS. 1-2) and configured for releasable engagement with a handle assembly similar to handle assembly 110 (FIGS. 1-2), are described hereinbelow. Each of the ablation devices includes one or more single-use or limited use features for inhibiting re-use or limiting the use of the needle electrode assembly. Further, any of the ablation devices described hereinbelow may include any or all of the features of ablation device 100 (FIGS. 1-2), described above, or any of the other ablation devices described herein.

Referring to FIGS. 3A-3B, ablation device 200 is shown generally including a handle assembly 210 and a needle electrode assembly 250 releasably engagable with handle assembly 210. Handle assembly 210 includes a housing 212 defining an engagement recess 216 for releasably engaging proximal end 252 of needle electrode assembly 250 therein. More specifically, housing 212 includes a pair of notches 218 defined therein adjacent engagement recess 216 that are configured to receive complementary protrusions 254 extending outwardly from proximal end 252 of needle electrode assembly 250 for releasably engaging needle electrode assembly 250 therein. Housing 212 of handle assembly 210 is ultimately coupled to an energy source, e.g., generator 20 (FIG. 1), and a cooling fluid source, e.g., cooling fluid source 30 (FIG. 1), for supplying energy and cooling fluid, respectively, to needle electrode assembly 250.

One or more electrical contacts 222 of handle assembly 210 are configured to electrically couple to one or more corresponding electrical contacts 272 of needle electrode assembly 250 upon mechanical engagement of handle assembly 210 and needle electrode assembly 250 to one another, thereby establishing electrical communication between handle assembly 210 and needle electrode assembly 250 for transmitting power and/or control signals between generator 20 (FIG. 1), the control circuitry (not explicitly shown) of handle assembly 210, and needle electrode assembly 250. Cooperating valves, e.g., valves 129, 179 (FIG. 2), of handle assembly 250 and needle electrode assembly 250 may also be provided to permit passage, e.g., inflow and outflow, of cooling fluid between the cooling fluid source 30 (FIG. 1) and hollow interior 274 of needle 270 of needle electrode assembly 250.

Needle 270 of needle electrode assembly 250 is formed from an electrically-conductive material, defines a hollow interior 274, and includes an insulative sleeve (or coating) 280 disposed about a portion of the external surface of needle 270. Needle 270 of needle electrode assembly 250, as shown in FIGS. 3A-3B, further includes a platform 278 that supports contacts 272 thereon. First and second arms 279 a, 279 b, respectively, extend from platform 278 and each include an outwardly-extending finger 279 c, 279 d, respectively, disposed at the free end thereof that is configured for engagement (along with protrusions 254) within notches 218 defined within housing 212 to maintain contacts 222, 272 in electrical communication to one another when handle assembly 210 and needle electrode assembly 250 are mechanically engaged to one another. Any other suitable mechanism for retaining platform 278 at proximal end 252 of needle electrode assembly 250 such that contacts 222, 272 are maintained in electrical communication with one another during use may also be provided.

Platform 278 of needle electrode assembly 250 is initially supported by one or more support members 290 adhered, engaged, or otherwise secured to the inner surface of needle 270. Platform 278 is also coupled to distal end 276 of needle 270 via a biasing member 294, e.g., a spring. Support members 290, as will be described in greater detail below, may be formed from a dissolvable or dispersable material, a contractible material, a collapsible structure (e.g., a collapsible scaffold), a phase-change material, or any other suitable material, member, component, or assembly, that is configured to transition between a first state, wherein support members 290 retain platform 278 and, thus, contacts 272 at proximal end 252 of needle electrode assembly 250, and a second state, wherein support members 290 no longer support platform 278, thus permitting platform 278 to retract distally into hollow interior 274 of needle 270 under the bias of biasing member 294.

Support members 290 may be configured to transition from the first state to the second state upon contact with one or more fluids, e.g., cooling fluid; support members 290 may be temperature-sensitive, e.g., wherein support members 290 transition from the first state to the second state upon heating to a pre-determined temperature; support members 290 may be chemically-sensitive, e.g., wherein support members 290 transition from the first state to the second state upon contact with a particular chemical (or chemicals); support members 290 may be electrically-sensitive, e.g., wherein support members 290 transition from the first state to the second state upon application of electrical energy thereto; and/or support members 290 may otherwise be configured to selectively transition from the first state to the second state. Further, support members 290 may alternatively or additionally include time-sensitive features such that support members 290 are transitioned from the first state to the second state, for example, upon exposure to one or more fluids, a pre-determined temperature, etc., for a pre-determined amount of time. In fact, needle 270 may include any suitable material, member, component, or assembly disposed within hollow interior 274 thereof that is configured to transition, upon occurrence of a particular event (or events), from a first state, wherein support members 290 retain platform 278 and, thus, contacts 272 at proximal end 252 of needle electrode assembly 250, and a second state, wherein support members 290 no longer support platform 278, thus permitting platform 278 to retract distally into hollow interior 274 of needle 270 under the bias of biasing member 294.

The assembly and operation of ablation device 200 is described with reference to FIGS. 3A-3B. As shown in FIG. 3A, needle electrode assembly 250 is initially disposed in a usable condition and, accordingly, platform 278 is retained at proximal end 252 of needle electrode assembly 250 via support members 290 (with support members 290 disposed in the first state). With needle electrode assembly 250 disposed in this usable condition, in preparation for use, needle electrode assembly 250 is inserted into recess 216 of housing 212 of handle assembly 210 to releasably engage handle assembly 210 and needle electrode assembly 250 to one another. Upon engagement of handle assembly 210 and needle electrode assembly 250 to one another, since support members 290 retain platform 278 and contacts 272 at proximal end 252 of needle electrode assembly 250, electrical contacts 222, 272 are likewise coupled to one another to electrically couple handle assembly 210 and needle electrode assembly 250 to one another. Valves, e.g., valves 129, 179 (FIG. 2), of handle assembly 210 and needle electrode assembly 250 may also be coupled to one another upon engagement of handle assembly 210 and needle electrode assembly 250 to one another to permit the inflow/outflow of cooling fluid therebetween.

With needle electrode assembly 250 mechanically engaged and electrically coupled to handle assembly 210, ablation device 200 is ready for use. The use of ablation device 200 is similar to that of ablation device 100 (FIGS. 1-2) described above and, thus, will not be repeated here. After use, needle electrode assembly 250 is disengaged from handle assembly 210 and is discarded or sterilized for re-use. Handle assembly 210 is configured as a reusable component and, thus, is sterilized for re-use. Alternatively, handle assembly 210 may be configured as a disposable component.

As mentioned above, the circulation of cooling fluid through hollow interior 274 of needle 270, the supply of electrosurgical energy to needle 270, heat, chemicals, and/or any other suitable occurrence after a pre-determined number of uses, a pre-determined number of sterilizations, and/or a pre-determine usage time, transitions support members 290 of needle electrode assembly 250 from the first state, shown in FIG. 3A, to the second state, shown in FIG. 3B. Upon transitioning of support members 290 from the first state to the second state, support members 290 no longer support platform 278 at proximal end 252 of needle electrode assembly 250 and, thus, platform 278 is retracted distally into hollow interior 274 of needle 270 under the bias of biasing member 294. This corresponds to the spent condition of needle electrode assembly 250.

In embodiments where support members 290 are transitioned from the first state to the second state during use, e.g., while needle electrode assembly 250 is still engaged to handle assembly 210, the engagement of fingers 279 c, 279 d of platform 278 within notches 218 of housing 212 maintains platform 278 at proximal end 252 of needle electrode assembly 250 during use. Accordingly, contacts 222, 272 remain coupled to one another, thus maintaining electrical communication between handle assembly 210 and needle electrode assembly 250 during use. However, once needle electrode assembly 250 is disengaged from handle assembly 210 (or in embodiments wherein support members 290 are transitioned from the first state to the second state when needle electrode assembly 250 is disengaged from handle assembly 210, e.g., during sterilization), platform 278 is retracted distally into hollow interior 274 of needle 270 under the bias of biasing member 294.

Alternatively, in embodiments where contacts 222, 272 are used to identify and/or verify needle electrode assembly 250 upon engagement to handle assembly 210 (while additional contacts are utilized to supply energy to needle electrode assembly 250), contacts 222, 272 need only be coupled to one another during the engagement of needle electrode assembly 250 and handle assembly 210 to one another to verify that an acceptable needle electrode assembly 250 is engaged to handle assembly 210 and/or to identify needle electrode assembly 250. Thus, contacts 222, 272 need not be retained in electrical communication with one another throughout the use of ablation device 200 but, rather, are permitted to be retracted within hollow interior 274 of needle 270 immediately upon occurrence of the pre-determined event(s) and without effecting the operation of ablation device 200. Accordingly, in such embodiments, fingers 279 c, 279 d, need not be provided.

Referring now to FIG. 3B, upon subsequent attempted use of needle electrode assembly 250 with needle electrode assembly 250 disposed in the spent condition, needle electrode assembly 250 may be mechanically engaged to handle assembly 210, but is inhibited from being electrically coupled to handle assembly 210 since contacts 272 are retracted within hollow interior 274 of needle 270. As such, reuse of needle electrode assembly 250 is inhibited once contacts 272 are retracted, e.g., the supply of electrical energy to (or identification of) needle electrode assembly 250 is inhibited. More specifically, depending on the configuration of support members 290, e.g., depending on what event(s) effect transitioning of support members 290 to the second state, use of needle electrode assembly 250 may be subsequently inhibited after a single use, a pre-determined number of uses, or a pre-determined amount of use time.

Turning now to FIGS. 4A-4B, another embodiment of an ablation device 300 provided in accordance with the present disclosure is shown generally including a handle assembly 310 and a needle electrode assembly 350 releasably engagable with handle assembly 310. Ablation device 300 is similar to ablation device 200 (FIGS. 3A-3B) and, thus, only the differences therebetween will be described in detail hereinbelow. More specifically, ablation device 300 differs from ablation device 200 (FIGS. 3A-3B) in that needle 370 of needle electrode assembly 350 does not include support members supporting platform 378 and a biasing member biasing platform 378 distally. Rather, platform 378 is initially retained at proximal end 352 of needle electrode assembly 350 via one or more retention elements 390.

Retention elements 390 may be formed at least partially from a shape memory material, or any other suitable material configured to transition between a first state, wherein retention elements 390 are extended, thus retaining platform 378 at proximal end 352 of needle electrode assembly 350 to facilitate electrical coupling of contacts 322, 372 to one another, and a second state, wherein retention elements 390 are contracted, thereby retracting platform 378 and contacts 372 distally into hollow interior 374 of needle 370 to inhibit electrical coupling of needle electrode assembly 350 and handle assembly 310 to one another. Similarly as described above with respect to support members 290 (FIGS. 3A), retention elements 390 may be configure to transition between the first and second states upon contact with one or more fluids, may be temperature-sensitive, chemically-sensitive, electrically-sensitive, and/or otherwise configured to selectively transition from the first state to the second state upon occurrence of any suitable event. Retention elements 390 may additionally or alternatively be time-dependent, similarly as described above.

Turning now to FIGS. 5A-5C, another embodiment of an ablation device provided in accordance with the present disclosure is shown generally identified by reference numeral 400. Ablation device 400 includes a handle assembly 410 and a needle electrode assembly 450 that defines a longitudinal axis “X′-X′” and is releasably engagable with handle assembly 410. Handle assembly 410 includes a housing 412 defining an engagement recess 416 for releasably engaging proximal end 452 of needle electrode assembly 450 therein. More specifically, housing 412 includes a pair of tabs 418 extending into engagement recess 416 that are configured to releasably retain proximal end 452 of needle electrode assembly 450 within engagement recess 416. Other releasable engagement mechanisms, e.g., snap-fit engagements, threaded-engagements, friction-fit engagements, etc., are also contemplated. Housing 412 of handle assembly 410 is configured to couple to an energy source, e.g., generator 20 (FIG. 1), and a cooling fluid source, e.g., cooling fluid source 30 (FIG. 1), respectively, for supplying energy and cooling fluid, respectively, to needle electrode assembly 450.

Continuing with reference to FIGS. 5A-5C, handle assembly 410 further includes a first contact pin 422 extending distally from housing 412 into engagement recess 416. First contact pin 422 is configured to electrically couple to a corresponding, second contact pin 472 disposed within hollow interior 474 of needle 470 of needle electrode assembly 450 upon mechanical engagement of handle assembly 410 and needle electrode assembly 450 to one another, thereby establishing electrical communication between handle assembly 410 and needle electrode assembly 450. More specifically, contact pins 422, 472, may be configured for establishing a conductive path for transmission of energy between generator 20 (FIG. 1) and needle electrode assembly 450 and/or for identifying or verifying the needle electrode assembly engaged with handle assembly 410. One or more contacts, e.g., contacts 122, 172, (FIG. 2), disposed on handle assembly 410 and needle electrode assembly 450 may additionally or alternatively be provided for similar purposes.

Needle 470 of needle electrode assembly 450 is formed from an electrically-conductive material, defines a hollow interior 474, and includes an insulative sleeve (or coating) 480 disposed about a portion of the external surface of needle 470. Needle 470 of needle electrode assembly 450 defines a proximal end 452 that is configured for engagement within engagement recess 416 defined within housing 412 of handle assembly 410 and an aperture 478 extending through proximal end 452 thereof in general alignment with longitudinal axis “X′-X′.” First contact pin 422 is configured for insertion into hollow interior 474 of needle 470 to permit engagement of needle electrode assembly 450 and handle assembly 410 to one another. Needle electrode assembly 450 further includes a second contact pin 472 disposed within hollow interior 474 of needle 470 and extending towards proximal end 452 thereof. Second contact pin 472 is initially disposed in a bent configuration (FIGS. 5A-5B), wherein a portion of contact pin 472 is bent, or displaced off of longitudinal axis “X′-X′,” thus permitting insertion of first contact pin 422 of handle assembly 410 through aperture 478 and at least partially into hollow interior 474 of needle 470. Second contact pin 472 is movable from this bent configuration to an aligned configuration (FIG. 5C), wherein second contact pin 472 is substantially aligned with longitudinal axis “X′-X”′ and aperture 478, thus inhibiting substantial insertion of first contact pin 422 through aperture 478 and into hollow interior 474 of needle 470. Second contact pin 472 of needle electrode assembly 450 may be formed from a ferromagnetic material, a shape-memory material, or any other suitable material configured to transition from the bent configuration to the aligned configuration upon occurrence of a pre-determined event(s), as will be described in greater detail below.

The assembly and operation of ablation device 400 is described with reference to FIGS. 5A-5C. As shown in FIG. 5A, needle electrode assembly 450 is initially disposed in an unused condition wherein second contact pin 472 is disposed in the bent configuration. In preparation for use, needle electrode assembly 450 is inserted into recess 416 of housing 412 of handle assembly 410 to releasably engage handle assembly 410 and needle electrode assembly 450 to one another. Engagement of handle assembly 410 and needle electrode assembly 450 is permitted at this point since second contact pin 472 is disposed in the bent configuration, thus permitting first contact pin 422 to be inserted through aperture 478 needle electrode assembly 450 and into hollow interior 474 of needle 470 sufficiently so as to permit engagement of handle assembly 410 and needle electrode assembly 450 to one another.

In the engaged position, as shown in FIG. 5B, first contact pin 422 extends through aperture 478 and into contact with the bent second contact pin 472, establishing electrical communication therebetween, e.g., for identification/verification of needle electrode assembly 450, transmitting energy to needle electrode assembly 450, and/or transmitting control signals between needle electrode assembly 450, handle assembly 410, and generator 20 (FIG. 1). Valves, e.g., valves 129, 179 (FIG. 2), of handle assembly 410 and needle electrode assembly 450 may also be coupled to one another upon engagement of handle assembly 410 and needle electrode assembly 450 to one another to permit the inflow/outflow of cooling fluid therebetween.

With needle electrode assembly 450 mechanically engaged and electrically coupled to handle assembly 410, ablation device 400 is ready for use. The use of ablation device 400 is similar to that of ablation device 100 (FIGS. 1-2) described above and, thus, will not be repeated here. After use, needle electrode assembly 450 is disengaged from handle assembly 410 and is discarded or sterilized for re-use. Handle assembly 410 is configured as a reusable component and, thus, is also sterilized for re-us, although handle assembly 410 may alternatively be configured as a disposable component.

With reference to FIG. 5C, in conjunction with FIGS. 5A-5B, as mentioned above, second contact pin 472 is transitionable from the initial, bent configuration (FIGS. 5A-5B) to the aligned configuration (FIG. 5C) upon occurrence of a pre-determined event (or events). For example, in embodiments wherein second contact pin 472 is at least partially formed from a ferromagnetic material, second contact pin 472 may be configured such that second contact pin 472 is initially retained in the bent condition, wherein second contact pin 472 is bent towards needle 470 due to magnetic attraction therebetween. Upon supply of electrosurgical energy to needle 470 during use (or the heat applied thereto during sterilization), second contact pin 472 is heated to or above its Curie point, thereby changing, e.g., eliminating, the magnetic field and allowing second contact pin 472 to return, in the absence of magnetic bias, to the aligned condition, as shown in FIG. 5C. When second contact pin 472 is disposed in the aligned position, needle electrode assembly 450 is correspondingly disposed in a spent condition.

Referring now to FIG. 5C, upon subsequent attempted use of needle electrode assembly 450 with needle electrode assembly 450 disposed in the spent condition, re-engagement of handle assembly 410 and needle electrode assembly 450 to one another is mechanically inhibited due to the disposition of second contact pin 472 in alignment with aperture 478. That is, second contact pin 472 inhibits first contact pin 422 from being sufficiently inserted into hollow interior 474 of needle 470, thus inhibiting proximal end 452 of needle electrode assembly 450 from being inserted sufficiently into engagement recess 416 of housing 412 so as to engage needle electrode assembly 450 and handle assembly 410 to one another. As such, repeated use of needle electrode assembly 450 is inhibited.

Turning now to FIG. 6, another embodiment of an ablation device provided in accordance with the present disclosure is shown generally identified by reference numeral 500. Ablation device 500 is similar to those ablation devices described above and generally includes a handle assembly 510 and a needle electrode assembly 550 releasably engagable with handle assembly 510. Handle assembly 510 includes one or more first contacts 522 configured to electrically couple to corresponding first contacts 572 of needle electrode assembly 550 such that power and/or control signals may be transmitted between generator 20 (FIG. 1) and needle electrode assembly 550 via the electrically-coupled first contacts 522, 572.

Handle assembly 510 further includes one or more second contacts 524 configured to electrically couple to corresponding second contacts 574 of needle electrode assembly 550 upon engagement of handle assembly 510 and needle electrode assembly 550 to one another to identify and/or verify needle electrode assembly 550. Second contacts 574 of needle electrode assembly 550 are coupled to one another via a destructive circuit or cell 590, e.g., a galvanic cell, that is configured to self-destruct, e.g., corrode, after initial coupling of second contacts 524, 574, of handle assembly 510 and needle electrode assembly 550, respectively, thereby rendering second contacts 574 of needle electrode assembly 550 inoperable. Accordingly, upon subsequent engagement of handle assembly 510 and needle electrode assembly 550 to one another, with second contacts 574 of needle electrode assembly 550 no longer operable, identification and/or verification of needle electrode assembly 550 is not established and, as a result, needle electrode assembly 550 is rejected by handle assembly 510 and/or generator 20 (FIG. 1). Thus, the destructive cell 590, e.g., the galvanic cell, inhibits reuse of needle electrode assembly 550.

Turning now to FIGS. 7A-7C, another embodiment of an ablation device provided in accordance with the present disclosure is shown generally identified by reference numeral 600. Ablation device 600 generally includes a handle assembly 610 and a needle electrode assembly 650 releasably engagable with handle assembly 610. Needle electrode assembly 650 of ablation device 600 is configured as a disposable component, e.g., needle electrode assembly 650 is disposable after a single use, a predetermined number of uses, or a predetermined amount of use time. Accordingly, needle electrode assembly 650 may include any of the limiting-reuse features of those ablation devices described above or, as will be described below, may incorporate a lockout mechanism 680 configured to inhibit reuse of needle electrode assembly 650. Handle assembly 610 of ablation device 600, on the other hand, is configured as a reusable component. Handle assembly 610, as will be described in greater detail below, is configured such that wear on the electrical contact(s) of handle assembly 610 for electrically coupling to needle electrode assembly 650 is substantially reduced. As a result, the life of handle assembly 610 can be extended without the concern of wearing due to repeated engagement/disengagement of needle electrode assembly 650 therewith.

Continuing with reference to FIGS. 7A-7C, handle assembly 610 of ablation device 600 includes a housing 612 defining an engagement recess 616 therein that is configured to receive proximal end 652 of needle electrode assembly 650 for releasably engaging needle electrode assembly 650 and handle assembly 610 to one another. More specifically, engagement recess 616 of housing 612 defines one or more notches 618 therein that are configured to engage protrusions 654 extending outwardly from proximal end 652 of needle electrode assembly 650 to releasably mechanically engage needle electrode assembly 650 and handle assembly 610 to one another. Other releasable engagement mechanisms, e.g., snap-fit engagements, threaded-engagements, friction-fit engagements, etc., are also contemplated. An electrical contact 622 extends about, e.g., lines, at least a portion of the inner surface of housing 612 that defines recess 616. Contact 622 is coupled to wires 623 that extend through housing 612 of handle assembly 610, ultimately coupling to a source of energy, e.g., generator 20 (FIG. 1). Handle assembly 610 may further be configured to couple to a cooling fluid source, e.g., cooling fluid source 30 (FIG. 1) for supplying cooling fluid to needle electrode assembly 650, similarly as described above. Housing 612 of handle assembly 610 of ablation device 600 further includes one or more activation members 636 disposed adjacent recess 616 and coupled to generator 20 (FIG. 1), or other suitable energy source, via wire(s) 637. The importance of activation members 636 will become more apparent below.

Needle electrode assembly 650 is similar to those described above and includes an electrically-conductive needle 670 defining a hollow interior 674, and an insulative sleeve (or coating) 680 disposed about a portion of the external surface of needle 670. Needle electrode assembly 650 further includes an electrical contact pin 672 extending proximally therefrom that is configured to couple to contact 622 of handle assembly 610 for identifying or verifying the identification of needle electrode assembly 650. One or more contacts, e.g., contacts 122, 172, (FIG. 2), disposed on handle assembly 610 and needle electrode assembly 650 may additionally or alternatively be provided for transmission of energy between generator 20 (FIG. 1) and needle electrode assembly 650. In either configuration, at least a portion of electrical contact pin 672 is formed from a transitionable material, e.g., a shape-memory material, or a ferromagnetic (or anti-ferromagnetic) material, such that, upon heating of contact pin 672 or upon introduction of an electromagnetic field to contact pin 672, contact pin 672 is transitioned between a first condition, as shown in FIGS. 7A and 7B, wherein contact pin 672 defines a generally linear configuration, and a second condition, as shown in FIG. 7C, wherein contact pin 672 is deflected to contact electrical contact surface 622 of handle assembly 610, thereby establishing electrical communication therebetween.

Needle electrode assembly 650, as mentioned above, may further include a lockout mechanism 680 disposed at the proximal end of needle electrode assembly 650 and configured to inhibit reengagement of needle electrode assembly 650 and handle assembly 610 after use. Lockout mechanism 680 includes a lockout member 682 disposed about contact pin 672 and defining an aperture 684 configured to permit passage of contact pin 672 therethrough. Lockout member 682 is formed from a transitionable material, e.g., a shape-memory material, or a ferromagnetic (or anti-ferromagnetic) material, and/or is coupled to needle electrode assembly 650 via a transitionable material, e.g., engagement member 686, such that, as will be described in greater detail below, lockout member 682 is movable from an initial position, wherein lockout member 682 does not protrude outwardly from needle electrode assembly 650, to an extended position, wherein, upon heating of lockout member 682 via activation members 636 or upon introduction of an electromagnetic field to lockout member 682 via activation members 636 (and/or via heating or introduction of an electromagnetic field to engagement member 686), lockout member 682 is biased to extend transversely through aperture 653 of needle electrode assembly 650 and outwardly from needle electrode assembly 650 to mechanically inhibit re-engagement of needle electrode assembly 650 to handle assembly 610.

Referring still to FIGS. 7A-7C, the assembly of needle electrode assembly 650 to handle assembly 610 is described. Initially, as shown in FIG. 7A, with contact pin 672 disposed in the first condition, and with lockout member 682 disposed in the initial position, proximal end 652 of needle electrode assembly 650 may be inserted into recess 616 of handle assembly 610 to releasably engage needle electrode assembly 650 therein, e.g., via the engagement of protrusions 654 within notches 618.

With reference to FIG. 7B, although needle electrode assembly 650 and handle assembly 610 are mechanically engaged to one another at this point, needle electrode assembly 650 and handle assembly 610 are not electrically coupled to one another. That is, with contact pin 672 disposed in the first condition, contact pin 672 extends into recess 616 in general spaced-apart relation relative to contact 622 of handle assembly 610. Likewise, at this point, lockout member 682 remains disposed in the initial position. As such, if needle electrode assembly 650 is engaged to handle assembly 610, but is not activated for use, lockout mechanism 680 is not triggered and, thus, disengagement and subsequent reengagement of needle electrode assembly 650 and handle assembly 610 is permitted.

Turning to FIG. 7C, in order to electrically couple needle electrode assembly 650 and handle assembly 610 to one another, activation members 636 are activated to heat or apply an electromagnetic field to contact pin 672. More specifically, in embodiments where contact pin 672 is formed from a shape memory material, activation members 636 function as heaters to sufficiently heat contact pin 672 so as to transform contact pin 672 from its austenite shape, e.g., the first condition, to its martensite shape, e.g., the second condition, thereby electrically coupling contact 672 to contact 622 of handle assembly 610. In embodiments wherein contact pin 672 is formed at least partially from a ferromagnetic material, activation members 636 function as electromagnets to apply an electromagnetic field to contact pin 672 such that contact pin 672 is deflected to the second condition, shown in FIG. 7C, wherein contact pin 672 is electrically coupled to contact 622 of handle assembly 610. With contacts 622, 672 coupled to one another, electrical communication is established between needle electrode assembly 650 and handle assembly 610, thus permitting use of ablation device 600, similarly as described above.

Simultaneously or near-simultaneously with the transition of contact pin 672 from the first condition to the second condition to electrically couple contact 672 of needle electrode assembly 650 to contact 622 of handle assembly 610, activation members 636 transition lockout member 682 and/or engagement member 686, e.g., via heating or applying an electromagnetic field thereto, such that lockout member 682 is urged from the initial position towards the extended position. However, at this point, the engagement of needle electrode assembly 650 within handle assembly 610 inhibits full extension of lockout member 682 to the extended position. Rather, lockout member 682 is not fully moved to the extended position until needle electrode assembly 650 is disengaged from handle assembly 610. Upon disengagement, lockout member 682 is biased to extend transversely through aperture 653 of needle electrode assembly 650 and outwardly from needle electrode assembly 650, e.g., the fully extended position, to mechanically inhibit re-engagement of needle electrode assembly 650 to handle assembly 610.

From the foregoing and with reference to the various figure drawings, those skilled in the art will appreciate that certain modifications can also be made to the present disclosure without departing from the scope of the same. While several embodiments of the disclosure have been shown in the drawings, it is not intended that the disclosure be limited thereto, as it is intended that the disclosure be as broad in scope as the art will allow and that the specification be read likewise. Therefore, the above description should not be construed as limiting, but merely as exemplifications of particular embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto. 

1-19. (canceled)
 20. An electrosurgical instrument, comprising: a housing including a first electrical contact; and an energy delivery device defining a longitudinal axis and configured to releasably couple to the housing, the energy delivery device including a second electrical contact configured to electrically couple to the first electrical contact upon coupling of the energy delivery device to the housing to establish electrical communication between the housing and the energy delivery device for delivering energy to tissue, the second electrical contact movable between a first position, wherein coupling of the energy delivery device to the housing is permitted, and a second position, wherein the second electrical contact prevents coupling of the energy delivery device to the housing.
 21. The electrosurgical instrument according to claim 20, wherein the second electrical contact is configured to: permit insertion of the first electrical contact into the energy delivery device when the second electrical contact is in the first position; and prevent insertion of the first electrical contact into the energy delivery deice when the second electrical contact is in the second position.
 22. The electrosurgical instrument according to claim 20, wherein the second electrical contact is configured to move from the first position to the second position upon heating of the second electrical contact.
 23. The electrosurgical instrument according to claim 20, wherein the second electrical contact is formed at least partially from one of a ferromagnetic material or a shape-memory material.
 24. The electrosurgical instrument according to claim 20, wherein an identity of the energy delivery device is determined based on electrical communication between the first and second electrical contacts.
 25. The electrosurgical instrument according to claim 20, wherein a number of uses of the energy delivery device is determined based on electrical communication between the first and second electrical contacts.
 26. The electrosurgical instrument according to claim 20, wherein the first electrical contact extends distally from a distal end portion of the housing.
 27. The electrosurgical instrument according to claim 20, wherein the energy delivery device defines a hollow interior configured to receive the first electrical contact upon coupling of the energy delivery device to the housing when the second electrical contact is in the first position.
 28. The electrosurgical instrument according to claim 20, wherein the housing defines a recess configured to releasably receive a proximal portion of the energy delivery device upon coupling of the energy delivery device to the housing when the second electrical contact is in the first position.
 29. The electrosurgical instrument according to claim 20, wherein the housing defines a tab configured to releasably retain a proximal portion of the energy delivery device within a recess defined by the housing upon coupling of the energy delivery device to the housing when the second electrical contact is in the first position.
 30. The electrosurgical instrument according to claim 20, wherein the second electrical contact is disposed parallel to the longitudinal axis when in the second position and disposed nonparallel to the longitudinal axis when in the first position.
 31. The electrosurgical instrument according to claim 20, wherein the energy delivery device defines a hollow interior configured to receive a cooling fluid upon coupling of the energy delivery device to the housing when the second electrical contact is in the first position.
 32. The electrosurgical instrument according to claim 20, wherein the second electrical contact is biased to the first position by a magnetic field.
 33. The electrosurgical instrument according to claim 32, wherein use of the energy delivery device is configured to eliminate the magnetic field biasing the second electrical contact to the first position such that the second electrical contact moves to the second position.
 34. An electrosurgical instrument, comprising: a first electrical contact pin extending from a housing; and a second electrical contact pin disposed within an energy delivery device and configured to electrically couple to the first electrical contact pin upon releasable coupling of the energy delivery device to the housing to establish electrical communication between the housing and the energy delivery device for delivering energy to tissue, the second electrical contact pin configured to: permit insertion of the first electrical contact pin into the energy delivery device when the second electrical contact pin is disposed in a first position such that coupling of the energy delivery device to the housing is permitted; and prevent insertion of the first electrical contact pin into the energy delivery device when the second electrical contact pin is disposed in a second position such that coupling of the energy delivery device to the housing is prevented.
 35. The electrosurgical instrument according to claim 34, wherein the second electrical contact pin is disposed parallel to a longitudinal axis defined by the energy delivery device when in the second position and disposed nonparallel to the longitudinal axis when in the first position.
 36. The electrosurgical instrument according to claim 34, wherein the first electrical contact pin extends distally from a distal end portion of the housing.
 37. The electrosurgical instrument according to claim 34, wherein the energy delivery device defines a hollow interior configured to receive the first electrical contact pin upon coupling of the energy delivery device to the housing when the second electrical contact pin is in the first position.
 38. The electrosurgical instrument according to claim 34, wherein the housing defines a recess configured to releasably receive a proximal portion of the energy delivery device upon coupling of the energy delivery device to the housing when the second electrical contact pin is in the first position.
 39. The electrosurgical instrument according to claim 34, wherein the second electrical contact pin is configured to move from the first position to the second position upon heating of the second electrical contact pin. 